1. Field of Invention
The present invention is concerned with a novel process for the preparation of certain pyrido[1,4]benzodiazepines which have antidepressant activity via novel [2-[(nitropyridinyl)amino]phenyl]arylmethanone precursors and the thioxomethyl, ketal or thioketal analogs thereof. Certain of these precursor compounds and derivatives which are part of the invention thereof have antidepressant activity.
2. Description of the Prior Art
Wander, A. in British Pat. No. 907,646 discloses preparation of certain dibenzodiazepines substituted with phenyl radicals on carbon and with alkyl or aminoalkyl radicals on the solitary bridging nitrogen. The method of preparation used by Wander is via cyclodehydration of orthoacyl aminodiphenylamines. Arylmethanones and pyrido compounds are not involved.
Japanese Pat. No. 73/43,520 (C.A. 80: 133501n) discloses preparation of dibenzodiazepines illustratively from 2-aminobenzophenones and ornithine.
[2-[(Aminopyridinyl)amino]phenyl]arylmethanones useful as antidepressant agents or as intermediates in a process for preparing certain pyrido[1,4]benzodiazepines are disclosed in U.S. application Ser. No. 305,080 filed Sept. 24, 1981. The method of preparation in that application involves starting with a haloaminopyridine rather than a halonitropyridine as in the present invention.